Pixar has created a variety of fun animated films, nearly all of which utilize a technique often used in caricature- non-human characters that are never the less central and personified. Animals, bugs, toys, cars, and robots- all which become central. In Up!, the talking dogs are given the explanation of collars invented that allow dogs to speak- both with the effect of personifying the dogs, and also bringing in a comedic element through the bridging of animal/human roles- the dogs still display a fair amount of dog traits, including a fascination with squirrels and impulse to chase thrown objects, while simultaneously assuming human-like roles.
WALL-E has a very interesting dynamic, with the robot story taking the front while an underlying story of future humans plays out. While the robots are not particularly verbally articulate, there is something resembling a robot love story playing out. The dual story lines help explore possible future issues, while keeping the story somewhat light and fun.
The final scenes of both movies have some aspects that are definitely within the realm of caricature. UP! has an old man fight, where both have back issues, and one spits out dentures as a defensive attack. There is also a dog fight featuring the "cone of shame". WALL-E features a captain/auto pilot fight, which is both amusing and triumphant- the humans of WALL-E are fat and taken everywhere in moving chair/computer things. The captain struggles to stand up, and eventually manages to many cheers. I'm told this seen also references/caricatures a film I've never seen ( 2001: A Space Odyssey).
Animation lends itself nicely to a combining caricature and comedy into stories. Pixar has done a nice job exploring that. I'm quite fond of Ratatouille, Monsters, Inc., Finding Nemo, and the animated shorts I've seen as well, but WALL-E and UP! are the most fresh in my mind. And UP! won as Oscar for best score this year. Very effective main theme.